Cave finder



J. J. CABOT April 9, 1929.

CAVE FINDER Filed Oct. 13, 1927 Patented Apr. 9, 1929.

miran s'rn'ras 1,708,354 PATENT FFICE.

JAMES J'. CABO'I, OF CHARLESTON, WEST VIRGINIA.

GAVE FINDER.

Application led October 13, 1927. Serial No. 225,956.

The invention relates to a novel device for use in drilling andoperating oil and gas wells. In some localities, it frequently happensthat the sands or earth in which a well is drilled or is being drilled,will crumble in some places so that the earth falls to the bottom of thewell, interfering with drilling or production, as the case may be. 'Ihecavities in the side of the well formed by these crumblings, are knownas caves and very often the difficulties can be much more effectivelyovercome if the well driller or operator is able to determine at whatdepth or depths, the cave or caves are sltuated. Hence, it is the objectof my invention to provide a unique device for accomplishing this end.

With the foregoing in view, the invention resides in the novel subjectmatter hereinafter described and claimed, the description beingsupplemented by the accompanying drawing.

Fig. 1 is a side elevation of a cave finder constructed in accordancewith my invention, showing the relation of parts which exists while thedevice is being lowered into a well.

Fig. 2 is a vertical longitudinal sectional view substantially on line2-2 of Fig. 1.

Fig. 3 is a view similar to Fig. 2 but illustrating thevmovements whichtake place when the device encounters a cave.

The drawing above brieiiy described, illustrates one specific embodimentof my invention and while the details disclosed will be ratherspeciiically described, it is to be understood at the outset, thatwithin the scope of the invention as claimed, variations may be made.

I make use of a vertically elongated body which is preferably in theform of a hollow rod 4, said rod being provided with a hollowcylindrical head 5 at its upper end to which a steel measuring line orthe like 6 may be connected, for instance by a screw cap 7. The lowerend of the rod 4 may also be provided with a head 8 which may ifnecessary be connected with a weight to assist in lowering the deviceinto a well.

A number of pairs of toggle links are disposed longitudinally of therods 4, the outer ends of said links being pivotally connected with theends of the rod, while the inner ends of said links are slidablyconnected with each other. Spring means are cmployed urging these linksoutwardly toward the position of Fig. 3 but they are normally heldagainst such outward movement by engagement with the wall ot a well.However, when a cave C is encountered as in Fig. 3, the toggle linksmove outwardly and I utilize this movement to operate a signal at thetop of the well. Then, by reading the measuring line 6, the depth atwhich the cave is located, may be readily determined.

In the present showing, the upper links 9 are comparatively short andthey are pivot-ed at 10 to lugs 11 projecting outwardly from the head 5.The lower links 12 however are ,of considerably greater length, thelower ends of these links being pivoted at 13 to the lugs 14 projectingfrom the head 8, while the upper ends of said links are slidablyconnected with the lower ends of the links 9. Preferably, these upperends of the links 12 curve inwardly and are formed with longitudinalslots 15 slidably receiving rivets or the like 16 which pass through thelower ends of the links 9. These same members 16 pass through the upperends of additional links 17 whose lower ends are pivotally connected inany desired manner as at 18, with a sleeve 19 which slidably surroundsthe rod 4, said sleeve being urged upwardly by a coiled compressionspring 20 which thrusts against a iiXed collar 21 on said rod. The links17 normally diverge upwardly and hence the upward thrust of the spring20, acting through the instrumentality of the sleeve 19 and the links17, tends to outwardly Jforce the toggle links 9-12, away from the rod4. The result is, that when the device reaches a cave such as C of Fig.3, spring 20 acts to outwardly force the toggle links and when suchoutward forcing takes place, a signal is operated at the top of thewell. The upward movement of the sleeve 19 and consequently the outwardmovement of the toggle links may be limited by an appropriate stopcollar 22 on the rod 4.

In the preferred form of construction, a stationary annular contact 23is mounted on the rod 4: and is insulated therefrom by a sleeve or thelike 24. A spring arm 25, constituting a movable contact, normallyengages the contact 28 and is secured at 26 to the sleeve 19. A wire 27is shown connected at 28 with the contact 23 and leading to one terminalof a battery 29 which is disposed above ground. The other terminal ofthis battery is shown connected by a wire 30 with a signal light 31which is in turn connected by a wire 32 with the measuring line 6.Hence, as long as contact 25 is in engagement with contact 23, the light31 will remain illuminated. However, when a cave is encountered and thetoggle links 9-12 move outwardly as in Fig. 3, contact 25 moves fromengagement with contact n3 as shown in this view, thus breaking thecircuit of the light 31 and extinguishing the latter, thereby notifyingthe operator that a cave has been reached. It is then an easy matter forhim to read the measuring line 6 and determine the depth at which thecave is located. lf some other line be used instead of the measuringline 6, the depth at which the cave is located, may be determined byactually measuring the length oi line which was lowered into the wellprior to extinguishing of the light 31, the measuring lbeingaccomplished as the device is again withdrawn from the well. Suchwithdrawal is readily permitted, as upon upward movement of the device,eiiected by pull upon the line or the like 6, the uppermost toggle links9 will engage the upper portion of the cave and will consequently beswung inwardly. Moreover, if the device is to be lowered further fromthe first cave encountered, this is readily permitted due to theinclination which the lower links 12 then assume, as when said device ispermitted to descend further, said links 12 will engage the lowerportion of the cave, thus again forcing the links inwardly. Upon suchinward movement, contact 25 again engages contact 23 and the light 31will remain illuminated as long as no additional cave is encountered.

As above stated, the details herein disclosed may be considered aspreferred. However, within the scope of the invention as claimed,variations may of course be made.

I claim:

1. A well cave finder comprising a vertically elongated rod to belowered into a well, a pair of toggle links extending longitudinally ofsaid rod, the inner ends of said links being pivotally and slidablyconnected with each other while the upper and lower ends respectively ofsaid links are pivotally connected with said rod, spring means tendingto outwardly move said links away from said rod, such movement beingprevented by the wall of the well until a cave is reached, andsignal-controlling means operatively connected with said toggle links tobe operated by outward movement thereof away from said rod.

2. A well cave finder comprising a vertically elongated rod to belowered into a well, toggle links extending longitudinally of said rodand pivoted at their outer ends thereto, the inner ends of said linksbeing pivotally and slidably connected, a sleeve slidable upon said rod,spring means acting to slide said sleeve in one direction, anl inclinedlink connecting said sleeve with the pivotally and slidably connectedends of said toggle links, and a signal-controlling means controlled bysliding of said sleeve.

3. A well cave finder comprising a vertically elongated rod to belowered into a well, toggle links extending longitudinally ot' said rodand pivoted at their outer ends thereto, the inner ends of said linksbeing pivotally and slidably connected, a sleeve slidable upon said rod,spring means acting to slide said sleevevin one direction, an inclinedlink connecting said sleeve with the pivotally and slidably connectedends of said toggle links, a contact arm secured to said sleeve andextending longitudinally therefrom, and a cont-act mounted on andinsulated from said rod for co-action with said contact arm incontrolling a signal circuit.

4. A well cave finder comprising a vertically elongated body, asignal-controlling member slidable on said body, an inclined linkpivoted at one end to said member, a second inclined link pivoted at oneend to the other end of the first named link, said second link beingpivoted at its other end to said body, and spring means tending to movethe pivotally connected ends of said links outwardly to effect slidingof said signal-controlling member.

5. A well cave nder comprising a vertically elongated rod to be loweredinto a well, upper relatively short links pivoted at their upper ends tothe upper 4portion of said rod and diverging downwardly with the latter,lower comparatively long links pivoted at their lower ends to the lowerportion of said rod and diverging upwardly with respect to the latter,the upper ends of said long links being curved inwardly and havinglongitudinal slots in their curved ends, pivots passing through thelower ends of the short links and through the slots of the long links,additional links having their upper ends pivotally mounted on the lastnamed pivots, said additional links converging downwardly, a sleeve towhich the lower ends of said additional links are pivoted, said sleevebeing slidable upon said rod, a collar spaced below said sleeve andsecured to said rod, a coiled compression spring surrounding said rodbetween said collar and sleeve and exerting an upward stress upon thelatter tending to outwardly swing the numerous links from the rod, andmeans connected with said sleeve for operating an alarm when said sleeveis permitted to slide upwardly by swinging of the links into a cave inthe wall of the well.

6. A well cave nder comprising a vertically elongated body, a signalcontrolling member slidable on said body, an inclined Vil() link pivotedat one end to said member, a second inclined link pivoted at one end tothe other end of the first named link, said second link being' pivotedat its other end to said body, spring means tending to move thepivotally Connected ends of said links outwardly to effect sliding ofsaid signaleontrolling member, and an additional and relatively longswingable link extending 10 from the pivotal connected ends of theaforesaid links to a distant point on said body, both ends of saidrelatively long, link being pivoted and provision being made at one ofsaid ends to permit the necessary sliding movement when all of the linksmove toward or from the body.

In testimony Wliereotl I have hereunto a'l'lixed my signature.

JAMES J. CABOT.

